The purpose of this shared instrumentation grant is to obtain funds to purchase an AMBIS Image Acquisition and Analysis System to be used by investigators in the Departments of Molecular Biology, Cellular Biology and Immunology at the Research Institute of Scripps Clinic. The Institute now contains a number of investigators using experimental approaches which involve quantitative analysis of 35S-, 14C-, 32P-labelled proteins and nucleic acids separated using one- and two-dimensional gel electrophoresis. Standard approaches using autoradiography and densitometry lack sensitivity, linearity and a dynamic exposure range to generate accurate quantitative results without either careful calibration of the film, or generation of multiple exposures for variable periods of time to obtain measurable results in the linear region of the film. All of the proposed studies now require the use of a AMBIS Imaging system which (1) is applicable to both 35S (14C) and 32P, (2) has a dynamic range of 5 orders of magnitude, eliminating the need for multiple exposures, (3) is approximately 20-fold more sensitive then standard autoradiographic approaches, greatly reducing the time-period for data acquisition, and (4) is highly quantitative, providing direct cpm determination in bands which require separation of less than 0.4 mm in Y-axis on one- or 2-dimensional gels. Acquisition of a Radioanalytic Imaging System will eliminate our current dependence on classical autoradiography and densitometry with its associated problems in reduced productivity due to insensitivity of the film and difficulties in accurate quantitation.